This is the headphone jack from a Macbook. I know what you’re thinking… Mac is a statement in engineering genius! This guy’s got a lot of gall to be writing about the Macbook. Well, you’d be wrong. I ran into this fun situation recently while visiting my in-laws.
My inlaws are Mac people. I don’t hold it against them. When we got to their house my mother in law was mildly distraught. Her precious Mac would no longer play sound! However, if they plugged in headphones it would play sound, but if they took the headphones out it wouldn’t play anything.
It sure sounded like the internal speaker had gotten damaged somehow. That was, until my father in law told me that when the Mac starts up without headphones plugged in that it still makes its telltale Mac startup noise. So the internal speaker clearly wasn’t totally broken.
Here’s what we knew:
- The startup sound came out of the internal speakers.
- If headphones were plugged in, all mac sounds came out of the headphones
- If headphones weren’t plugged in, the headphone jack would turn red BUT the volume slider on the menu bar would be locked. Also, when pressing the volume buttons on the keyboard it would display a little X below the volume. You couldn’t change it.
- If you started playing sounds without the headphones in the volume control would be locked. Once the headphone jack was fully in the volume control would become unlocked.
Clearly something was odd about this engineering. The mac recognizes three states rather than the expected two.
- The internal speakers are on, nothing is in the headphone jack. Sound comes out through the speakers.
- The internal speakers are off, something is partially in the headphone jack. No sound comes out anywhere, but the volume control is locked.
- The internal speakers are off, something is in the headphone jack. Sound comes out of the headphones, the volume control is enabled.
And it was this set of facts that led me to the solution and conclusion that this headphone jack was overengineered. So, took the headphone plug, put it in about halfway and started jiggling it left and right. And ta-da, the music started playing out of the main speakers again. Problem solved.
Why do I consider this overengineering? What’s the point of the second state in the three possible states above? Clearly, you have some way of knowing when the headphone jack is fully in because that’s when you enable the volume control. So what’s the point of the halfway control? Why would I want to disable the external speaker and not enable the headphones? It’s just dumb.
March 15, 2009 at 3:48 am |
I think you will find the red glow is due to the MacBook’s digital optical audio-out. It’s not just an analog port. That also explains your 2nd state.
March 15, 2009 at 7:15 am |
My point isn’t about what it’s for, but that it’s silly engineering to have a system which shuts off the audio even though something isn’t plugged in. It can be optical or analog; it still should switch over from internal speakers to the audio jack in a single mechanism.
The volume slider didn’t become enabled for the audio jack in the half-state, so I presume the optical output would have to trigger the second further down switch as well to complete the transition from internal speaker to plugged in device.